Question 192102
basic  form  is   Ax^2+Bx+C=0   for  using  quadratic  eqn  to  solve  for  x

your  eqn  is  2x^2-5x =1

subt  1  both  sides

(2)x^2 +(-5)x +(-1) =0

therefore  A=(2),  B=(-5),  C=(-1)

standard  form  of  quadratic  eqn  is   Ax^2+Bx=C

in  which  case  a=(2),  B=(-5),  but  C=(+1)

check  which  problem  you  have